Particle accelerators are generally known in the art and are devices that use electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. Large accelerators are best known for their use in particle physics as colliders (e.g. the Large Hadron Collider (LHC) at CERN, RHIC, and Tevatron). Other kinds of particle accelerators are used in a large variety of applications, including particle therapy for oncological purposes, and as synchrotron light sources for the study of condensed matter physics.
Conventional particle accelerators are configured with large, high-voltage stages to form a traveling high voltage wave or a gradient along the axis of a coaxial arrangement of cells. Linear induction accelerators are basically a number of stacked voltage sources that produce a transient high electric field gradient by the sequential pulses provided by the circumventing transmission lines, all timed as the initial particle pulse propagates along the axial line of the structure. Exemplary configurations of particle accelerators are disclosed in U.S. Pat. No. 5,757,146 to Carder, titled “High-gradient compact linear accelerator,” and U.S. Pat. No. 7,710,051 to Caporaso et al., titled “Compact accelerator for medical therapy,” each of which are incorporated by reference in their entirety herein. Such configurations are based off of Asymmetric Blumlein designs, which form a fast and a slow wave after a single switch (per Blumlein assembly) is triggered. In these configurations a switch is required for each transmission line. In the configuration of U.S. Pat. No. 5,757,146, many switches are required for each line and, in the case of U.S. Pat. No. 7,710,05, one switch is required for each Blumlein assembly, and as many as 4 Blumleins are required for each accelerating stage.
Another disadvantage of the aforementioned designs is the requirement of two different dielectrics, per Blumlein, to form the slow and fast waves that travel as each switch is triggered. These fast and slow moving waves are required for the electric field gradient to align in phase as the particle travel along the axis of the structure. This complex dielectric interfacing and timing make their use non-practical for the non-expert and reduces the efficiency of the energy coupled to the particle beam as it travels down the structure.
Regardless of the use of lasers, the switching complexity for such structures presents problems of reliability, efficiency, and/or cost, in addition to scalability. While such designs lay claim to being “compact”, they nevertheless are heavy (e.g., tons of pounds in weight), and require a cumbersome hospital structure with a dedicated room, typically several meters height and tens of square meters in surface area. Other problems with the aforementioned conventional designs relate to power requirements. Such devices cannot be made human portable (e.g., handheld or implantable) due to the fact that each switch wastes a substantial amount of energy just through switch impedance. As all switches act as sinks of energy, the energy efficiency of a device decreases as more switches are added to the design.